The US government doesn’t want an adversary government to have the data of its citizens (because of varios reasons, including mass manipulation for example). They would of course have no issue with having that data themselves though (also because then they would be more in control over how the data is handled).
Of course it does. OP asked multiple questions, this was sipposes to answer why they used KDE instead of Gnome. I personally think Arch would have the advantage of having the newewst drivers, Proton version etc. available.